Agriculture Reference
In-Depth Information
18. Sow health
R.M. Friendship
*
and T.L. O'Sullivan
Department of Population Medicine, University of Guelph, Guelph, ON, N1E 2W1,
Canada;
rfriends@uoguelph.ca
Abstract
The control of disease in the sow herd helps prevent disease spread through other stages
of production and attention to sow health status can be key to creating herd immunity
and, possibly, to the elimination of production-limiting diseases. Sows provide passive
immunity for suckling piglets. Ideally a strong healthy piglet will be weaned and not
a weak, infected piglet that will pass disease to pen-mates in the nursery. High sow
mortality and premature culling due to illness and injuries result in lowered herd
productivity because sows are removed before they reach maximum productivity and
are replaced by less productive gilts. Farrowing is a period when the sow is vulnerable
to health issues, such as uterine infections and mastitis, and is more prone to systemic
infections such as erysipelas. Major causes of sudden death in sows, include hemorrhage
due to gastric ulcers and gastrointestinal torsions, as well as heat stress, pylonephritis and
heart failure. Sows are generally immune to most endemic diseases present on the farm
because of previous exposure but some pathogens, when newly introduced, can cause
herd outbreaks of disease involving the sows. For example, porcine reproductive and
respiratory syndrome virus and swine influenza virus can result in widespread sow illness
and possibly sow mortality. More often the consequences of sows becoming infected with
a swine pathogen result in the most serious losses occurring to the fetuses or the suckling
piglets. Reproductive losses that occur with an infection of parvovirus cause heavy losses
to embryos and fetuses but generally no signs of illness in the dam. Diseases that do cause
illness to the sow during lactation may result in high piglet mortality because the sick sow
may not provide sufficient milk to prevent starvation of her piglets. To maximize herd
performance, sow health must be optimized.
Keywords:
disease, herd immunity, sow mortality, mastitis, lameness
18.1
Introduction
Sow health has an impact on not just the performance of the breeding herd but on all
stages of the production cycle. In this chapter the importance of the health status of the
sow population in preventing or minimizing the spread of disease through the nursery
and grower-finisher stages will be discussed as well as management procedures to reduce
disease problems in the sow herd such as routine vaccination and parasite control
programs. Finally, some of the important diseases of sows will be presented.
